At the time of my retirement (age 59), we annuitized 10% of the value of our joint retirement portfolio value through an SPIA, to provide us with a base income, that was not influenced by the varience of the market.
Almost five years later in retirement, I would say (for us) it was one of the "smart" financial decisions in our lives.
For us, it was the fact that I retired early (at least earlier than most) without a pension, and with the decision to delay SS till age 70 - an eleven year span.
This allows me to delay SS till age 70, thus maximize my DW's survivor benefits, allow me to accumulate an increase in SS by 8%/year (in addition to any COLA's during that period) from ages 66-69, and be able to claim against DW's benefit at age 66 at a 50% rate (we're the same age). BTW, that will be a "superior annuity", COLA adjusted, and our current SPIA? Just added as additional income stream.
I'll be the first to say that an annuity is not for everybody; you need to have a reason (well thought out) to persue such an action. Part of the decision was made by running different scernieos through the use of various (free) forcast models, such as FireCalc, RIP (Fidelity), and FE (Vanguard) to see if the option would be applicable to your personal situation. In our case (only), the addition of the SPIA greatly increased the return, and the viability of our personal plan.
BTW we have no regrets, and will seriously consider additional SPIA income streams as we age...